[petsc-users] snes true and preconditioned residuals for left npc

[Barry Smith]

> On Jul 6, 2016, at 12:17 PM, Xiangdong <epscodes at gmail.com> wrote:
> 
> Hello everyone,
> 
> I am using snes_type aspin, which is actually newtonls + npc (nasm). After each newton iteration, if I call SNESGetFunction, the preconditioned residual is obtained. However, if I use SNESComputeFunction, I get the  true (unpreconditioned) residual. 
> 
> If I want to know the preconditioned residual at a point different from current solution, which function should I call?

  I don't think it is possible.

  Barry

> 
> Thanks.
> 
> Best,
> Xiangdong